Predator got my mallard and domestic ducks

I'm hoping someone can help me figure out what got my ducks!!!
My mallard female was eaten, cleanly, at both ends. We found her under/behind a a partition she liked to sleep under.
We found the larger domestic 40' away. She was drug out of the pen through the pasture at the back of the barn, under a gate and left partially eaten under the deck floor of our barn. I think whatever it was ambushed them while they were sleeping sometime during the night maybe early morning.
They were in an enclosed pen. They ate the mallard on the spot and left her. The domestic had to be dragged from her house and under several gates. The only mess was a few fluffy short feathers out in the open by their pool. The domestic had her breast eaten. No foot prints to speak of.
Any ideas? Skunk, possum, cat?

My experience when the breast is eaten and the bird is left where killed its a raccoon. Having one bird drug that far throws me a bit but if the raccoon has kits she may have been trying to take it to them.

What's so odd is we've never seen a raccoon anywhere near here. Plus, both ducks are dead and partially eaten, the mallard more so, both front and back are gone with only the middle left intact. We are going to set up a live trap with the remains of the mallard in the trap and put it in the chicken pen tonight with a game camera. It will likely return for the rest of its kill.

Bigger question how did it get in the pen to kill the ducks? I lost so many ducks over the years and never saw the killer. Each time I thought the aviary was secure another kill would happen. Sometimes the ducks eaten sometimes just head ripped off. Could be raccoon or fox or bobcat or feral cat you've got! Trail cam and trap should help figure it out! I set traps and caught raccoons and feral cats but killing continued. The killer climbed posts and ripped thru aviary netting. Covered netting around all posts with wire and would still get in.